(Hicars)Sporting its signature light blue paint scheme, as well as prominent “Hybrid Vehicle” stickers, BMW’s upcoming X6 ActiveHybrid prototype made a road trip last weekend to Austin, Texas, where we spotted it hanging out just a block from the state capitol. Appearing production-ready, the X6 ActiveHybrid is only visually set apart by a hood bulge and a small blue efficiency gauge where the fuel economy gauge would be on a standard gas model.

We first saw BMW’s X6 ActiveHybrid Concept at the Frankfurt Motor Show, and BMW is wasting no time with real-time development, and you’re even looking at the production sheet-metal with the lightly bulged hood. We’re even hearing rumors that the X6 ActiveHybrid will be available in just one color — the light blue seen here.

While it remains unclear what engine will be coupled with the hybrid powertrain, the X6 ActiveHybrid will use a version of the two-mode hybrid system that was developed with General Motors and Daimler.

Like GM’s two-mode hybrid vehicles, the X6 ActiveHybrid will be able to be powered by the electric motor on its own or in tandem with SAC’s internal combustion engine, and will also feature regenerative braking. The system is said to boost fuel-economy in the X6 by 20 percent overall.

While BMW has yet to announce when the hybrid version of the X6 will hit the market, sources say it could be as soon as late 2009 as a 2010 model. We expect its first show arrival to be at the Frankfurt Motor Show in September. (BMW X6 ActiveHybrid)